That is a good point: I have some gadgets plugged in: dash cams and Magsafe chargers. But all of that is on the USB plugs that switch off with the car. I did unplug all of that and the OBD2 dongle just to be sure. Unfortunately, I see the same behavior with all of the toys unplugged....
I think you may have missed my warning about using a charger that's 3 amps or less. I guess the one you got only has a 2A fuse, so you're limited to a 2A charger or less.
no, it was working, just fine until I made the mistake of turning the car ON while it was connected that’s when the fuse blew. the charger when it first connected doesn’t start charging till the button is pressed to set the charge level first. It’s just a digital read out of the battery charge.
Well if you turned the car on, the output of the charger would have been hit with 15V suddenly, and that might have fried it if it's a cheap 12V charger. The Vgate wouldn't work unless there's 12V at the OBDII port.
. Charger now working on 0.8A mode. ?
No offense, but that charger is cheap crap. Spend money on something decent like a CTEK. I see it charges all the way past 15V, which is going to damage the AGM. On trickle charge it shouldn't go higher than 13.8V. Do not let it sit above 14V for more than a few hours.Definitely a dumb move turning on the car!
I thought maybe I fried the charger and not a chip or fuse in the car. But I checked the charger a 12v spare battery direct connection and it worked. As I mentioned when 1st connected it displays a battery voltage readout. It needs a 12V or 6 V connection to activate, other display just flashes. Maybe I blew something in the OBD adapter to clips.
I just was a bit frightened it did something in the car. Type is Auto XS. It has 3 Modes 0.8A for batteries up to 120 Ah charging and 3.8a & 3.8a Cold. 15.1 V cut off. Auto Trickle charge current 50–150 mA.
UPDATE: checked continuity in OBD cable to (+) ?, Fuse OK, then found tiny spring inside fuse folder missing, must have popped out changing fuse. . Connected multimeter 11.9 Vdc
At this point I recommend you disconnect everything, put it in the trash, and pray you didn’t damage your car. Do not use a battery saver device with alligator clips! If the positive clip touches any metal you short out the OBD port.
I will second this. Learn from my mistakes: just because you can make a DIY solution does not mean you should. On a previous car I had, I tried to wire in a high current USB charger to the vehicle wiring harness behind the OBD port. I goofed somehow and the trunk opening motor fried along with the wire to it melted. That was a $300 mistake. I should have just bought a 12v car lighter adapter with 2amp charing.
